scholarly journals Thermal and electric Characteristics of High-power Short-duration Radiofrequency Ablation and Standard Radiofrequency Ablation: A Computer Simulation Study

Author(s):  
Kaihao Gu ◽  
Shengjie Yan ◽  
Xiaomei Wu

Abstract Background: High power-short duration ablation is an emerging conception for cardiac RF treatment. But the biophysical ablation properties of this technique have not been fully explored. This study compared the electric field characteristics and thermal lesion dimension in High power-short duration (HP-SD) radio frequency (RF) ablation and standard RF ablation by using the finite element method. Results: The results demonstrated that the lesion size and temperature in HP–SD RF ablation increased faster than standard RF ablation. The thermal lesion volume in both ablation modes demonstrated a linear increase and the rate of increase of HP–SD RF ablation grew faster than that of standard RF ablation. For HP–SD application at 50 W for 5 s, the lesion depth was shallower (1.74 to 2.1 mm vs 2.40 to 3.15 mm) and the surface lesion diameter was broader (2.76 to 3.32 mm vs 2.42 to 2.66 mm) than that for standard RF ablation at 25 W for 30 s. Conclusion: Compared with standard RF ablation, HP–SD RF ablation creates a broader lesion width and surface lesion diameter but shallower lesion depth, with a faster increase in temperature. HP–SD ablation is more able to achieve uniform and contiguous lesion shape, which is a suitable for point-to-point RF ablation procedures.Higher temperature was formed in deeper space of cardiac tissue in HP–SD ablation. The duration of HP–SD ablation should be strictly controlled for preventing the steam occur in tissue.

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
J Schreieck ◽  
D Heinzmann ◽  
C Scheckenbach ◽  
M Gawaz ◽  
M Duckheim

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Local impedance (LI) drop can predict sufficient lesion formation during radiofrequency ablation (RF). Recently, a novel ablation catheter technology able to measure LI and contact force has been made available for clinical use. High power short duration (HPSD) RF ablation has been shown to be feasible for atrial fibrillation (AF) ablation with short procedure time. We used LI drop and plateau formation to guide duration of 50 Watt RF power applications for circumferential pulmonary vein isolation (PVI). Methods Consecutive patients with indication for de novo AF ablation (n = 32, age 65 ± 10 years) with paroxysmal (n = 16) or persistent (n = 16) AF underwent ultra high density 3D mapping of the left atrium and catheter ablation. Thereafter, ipsilateral PV encircling with 50 Watt RF-applications targeting an interlesion distance of ≤ 6mm and a contact force of 10-30g was performed. Duration of HPSD RF application between 7-15s was guided by impedance drop >20 Ohm and plateau formation of LI. Further ablation strategy was left to the investigator’s discretion. Esophageal temperature measurement was performed using a three thermistor catheter with temperature cut off 39.0°C. In case of temperature rise or very near esophageal contact to the circumferential line, RF application time was shortened to 7s. Patients underwent adenosine testing after PVI. Previously we performed all types of AF ablation using an LI guided HPSD ablation without contact force measurement capability in 80 patients. Results Complete PVI was achieved in all pts with only 13.5 ± 4.3 min cumulative RF application duration and an ablation procedure duration of 46.5 ± 10.4 min with the novel LI measuring catheter. First-pass isolation of ipsilateral veins was achieved in 75% of circles. Recurrence of PV conduction during waiting period (20min) and adenosine testing occured in 25% of circles, and was reablated in most patients with a single spot of HPSD application. Using 94 ± 36 RF application per patient, mean maximum LI drop was 23.6 ± 4.0 Ohm. Reconnected fibers were associated with low LI drop due to instability of contact in most cases due to breathing in case of difficult sedation of the patients. No serious complications occurred in all 32 pts using HPSD with the novel contact force catheter design. Conclusion Guiding of HPSD RF ablation by LI is highly efficient and safe. A novel local impedance algorithm in combination with contact force sensing enable short PVI times with low early recurrence of PV conduction. Prediction of permanent lesions seems possible and the only limitation seems to be unstable RF catheter contact due patients breathing. Follow up have to be waited.


2021 ◽  
Author(s):  
Marcela Mercado-Montoya ◽  
Tatiana Gomez-Bustamante ◽  
Enrique Berjano ◽  
Steven Mickelsen ◽  
James Daniels ◽  
...  

2018 ◽  
Vol 29 (11) ◽  
pp. 1570-1575 ◽  
Author(s):  
Felix Bourier ◽  
Josselin Duchateau ◽  
Konstantinos Vlachos ◽  
Anna Lam ◽  
Claire A. Martin ◽  
...  

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Kulstad ◽  
M Mercado-Montoya ◽  
S Shah

Abstract Introduction Recent clinical data show that high-power, short-duration (HPSD) radiofrequency (RF) ablation can result in a similar esophageal injury rate as traditional low-power, long-duration (LPLD) ablation. Existing methods to prevent esophageal injury have yielded mixed results and can result in prolonged procedure time, potentially increasing the incidence of post-operative cognitive dysfunction. A new esophageal cooling device currently available for whole-body temperature modulation is being studied for the prevention of esophageal injury during LPLD RF ablation and cryoablation. We sought to develop a mathematical model of HPSD ablation in order to quantify the capability of this new esophageal cooling device to protect from esophageal injury under high-power conditions. Methods Using a model we developed of HPSD RF ablation in the left atrium, we measured the change in esophageal lesion formation and the depth of lesions (measured as percent transmurality) with the esophageal cooling device in place and operating at a temperature from 5°C to 37°C. Tissue parameters, including thermal conductivity, were set to average values obtained from existing literature, and energy settings were evaluated at 50W for between 5 and 10 seconds, and at 90W for a duration of 4 seconds. Results Esophageal injury as measured by percent transmurality was considerably higher at 50W and 10s duration than at 90W of power with 4s duration, although both settings showed potential for esophageal injury. The protective effect of the esophageal cooling device was evident for both cases, with a greater effect when using 50W for 10s (Figure 1). At the coldest device settings, using a 5 min pre-cooling period also reduced the transmurality of the intended atrial lesions. Esophageal protection in HPSD ablation Conclusions Esophageal cooling with a new patient temperature management device shows protective effects against thermal injury during RF ablation across a range of tissue thermal conductivity, using a variety of high-power settings, including 90W applied for 4 seconds. Adjusting the cooling power by adjusting the circulating water temperature in the device allows for a tailoring of the protective effects to operating conditions. Acknowledgement/Funding Attune Medical


2020 ◽  
Vol 8 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Irum D Kotadia ◽  
Steven E Williams ◽  
Mark O’Neill

High-power, short-duration (HPSD) ablation for the treatment of AF is emerging as an alternative to ablation using conventional ablation generator settings characterised by lower power and longer duration. Although the reported potential advantages of HPSD ablation include less tissue oedema and collateral tissue damage, a reduction in procedural time and superior ablation lesion formation, clinical studies of HPSD ablation validating these observations are limited. One of the main challenges for HPSD ablation has been the inability to adequately assess temperature and lesion formation in real time. Novel catheter designs may improve the accuracy of intra-ablation temperature recording and correspondingly may improve the safety profile of HPSD ablation. Clinical studies of HPSD ablation are on-going and interpretation of the data from these and other studies will be required to ascertain the clinical value of HPSD ablation.


Author(s):  
Hagai D. Yavin ◽  
Zachary P. Bubar ◽  
Koji Higuchi ◽  
Jakub Sroubek ◽  
Mohamed Kanj ◽  
...  

Background: High-power short-duration (HP-SD) radiofrequency ablation (RFA) has been proposed as a method for producing rapid and effective lesions for pulmonary vein isolation. The underlying hypothesis assumes an increased resistive heating phase and decreased conductive heating phase, potentially reducing the risk for esophageal thermal injury. The objective of this study was to compare the esophageal temperature dynamic profile between HP-SD and moderate-power moderate-duration (MP-MD) RFA ablation strategies. Methods: In patients undergoing pulmonary vein isolation, RFA juxtaposed to the esophagus was delivered in an alternate sequence of HP-SD (50 W, 8–10 s) and MP-MD (25 W, 15–20 s) between adjacent applications (distance, ≤4 mm). Esophageal temperature was recorded using a multisensor probe (CIRCA S-CATH). Temperature data included magnitude of temperature rise, maximal temperature, time to maximal temperature, and time return to baseline. In swine, a similar experimental design compared the effect of HP-SD and MP-MD on patterns of esophageal injury. Results: In 20 patients (68.9±5.8 years old; 60% persistent atrial fibrillation), 55 paired HP-SD and MP-MD applications were analyzed. The esophageal temperature dynamic profile was similar between HP-SD and MP-MD ablation strategies. Specifically, the magnitude of temperature rise (2.1 °C [1.4–3] versus 2.0 °C [1.5–3]; P =0.22), maximal temperature (38.4 °C [37.8–39.3] versus 38.5 °C [37.9–39.4]; P =0.17), time to maximal temperature (24.9±7.5 versus 26.3±6.8 s; P =0.1), and time of temperature to return to baseline (110±23.2 versus 111±25.1 s; P =0.86) were similar between HP-SD and MP-MD ablation strategies. In 6 swine, esophageal injury was qualitatively similar between HP-SD and MP-MD strategies. Conclusions: Esophageal temperature dynamics are similar between HP-SD and MP-MD RFA strategies and result in comparable esophageal tissue injury. Therefore, when using a HP-SD RFA strategy, the shorter application duration should not prompt shorter intervals between applications.


2020 ◽  
Vol 31 (6) ◽  
pp. 1332-1339 ◽  
Author(s):  
Felix Bourier ◽  
Konstantinos Vlachos ◽  
Antonio Frontera ◽  
Claire A. Martin ◽  
Anna Lam ◽  
...  

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